Index-Based Dietary Patterns and Inflammatory Bowel Disease: A Systematic Review of Observational Studies

Diet is one of the most critical factors for inflammatory bowel disease (IBD). A whole dietary pattern should be considered when doing nutrient-based research to preserve the potential for synergism between nutrients. Dietary indices are important tools to evaluate diet quality, and we investigated the associations of it with IBD. Fourteen studies on the relation between index-based dietary patterns and IBD were included. 6 studies showed the relation between index-based dietary patterns and IBD risk, 7 studies explored the dietary indices and progression of IBD, and 1 study investigated the relationship between index and all-cause mortality in IBD patients. These results implied that a high score on the Mediterranean diet was negatively associated with risk and progression of IBD. However, a diet with high inflammatory potential could increase risk and aggravate disease activity in IBD. Dietary scores have the potential to evaluate the association between overall diet quality and risk and progression of IBD. Future randomized controlled trials are required to confirm the effect of the change in dietary score. This review was registered at www.crd.york.ac.uk/prospero/ as CRD42020220926.